Dynamic expression of synemin isoforms in mouse embryonic stem cells and neural derivatives

Abstract

BackgroundIntermediate filaments (IFs) are major components of the mammalian cytoskeleton and expressed in cell-type-specific patterns. Morphological changes during cell differentiation are linked to IF network remodeling. However, little is known concerning the presence and the role of IFs in embryonic stem (ES) cells and during their differentiation.ResultsWe have examined the expression profile of synemin isoforms in mouse pluripotent ES cells and during their neural differentiation induced by retinoic acid. Using RT-PCR, Western blotting and immunostaining, we show that synemin M is present at both mRNA and protein levels in undifferentiated ES cells as early as pluripotency factor Oct-3/4 and IF keratin 8. Synemin H was produced only in neural precursors when neural differentiation started, concurrently with synemin M, nestin and glial fibrillary acidic protein. However, both synemin H and M were restricted to the progenitor line during the neural differentiation program. Our in vivo analysis also confirmed the expression of synemins H/M in multipotent neural stem cells in the subventricular zone of the adult brain, a neurogenic germinal niche of the mice. Knocking down synemin in ES cells by shRNA lentiviral particles transduction has no influence on expression of Oct4, Nanog and SOX2, but decreased keratin 8 expression.ConclusionsOur study shows a developmental stage specific regulation of synemin isoforms in ES cells and its neural derivatives. These findings represent the first evidence that synemins could potentially be useful markers for distinguishing multipotent ES cells from undifferentiated neural stem cells and more committed progenitor cells.

Synemin acts as a regulator of signalling molecules in skeletal muscle hypertrophy

“…We previously reported that b-synemin is expressed in pluripotent embryonic stem cells, and both a-and b-synemin are expressed in multipotent neural stem cells in the subventricular zone of the adult brain (de Souza Martins et al, 2011). We also found that synemin protein is present in satellite cells.…”

“…Three synemin isoforms differing in their C-terminal tails -a-synemin (also known as synemin H, 180 kDa), b-synemin (also known as synemin M, 150 kDa) and synemin L (41 kDa) -are produced by alternative splicing and are differentially regulated during embryonic development (Titeux et al, 2001;Xue et al, 2004). b-synemin is expressed in pluripotent embryonic stem cells, whereas both a-and bsynemin are expressed in multipotent neural stem cells in the subventricular zone of the adult brain (de Souza Martins et al, 2011). Importantly, synemin expression is upregulated in pathological conditions such as neurotrauma or Alexandre disease, a neurodegenerative disorder, and loss of its expression is associated with aggressive forms of breast cancer (Jing et al, 2005;Jing et al, 2007;Noetzel et al, 2010;Pekny et al, 2014).…”

Desmin enters the nucleus of cardiac stem cells and modulates Nkx2.5 expression by participating in transcription factor complexes that interact with thenkx2.5gene

“…In fibroblasts these fusion proteins integrated well in the pre-existing vimentin IF network but displayed a diffuse and spotty staining in the cytoplasm of undifferentiated ESCs and CVPCs ( ) which express vimentin and cytokeratins but most likely do not contain IFs ( de Souza Martins et al, 2011 ; Gao et al, 1994 ). Although expressed under the control of the CMV promoter in all cells, mCherry-tagged desmin was found in nuclei of less than 10% of the differentiating CVPCs ( …”

Gene Expression Changes in Progression of Cervical Neoplasia Revealed by Microarray Analysis of Cervical Neoplastic Keratinocytes

“…An interesting characteristic of CIN2 and CIN3 keratinocytes is the disruption of cell‐differentiation programs. Indeed, a series of differentiation‐induced genes, such as ALDH1A3 (Muzio et al, ), IRX2 (Lewis et al, ), IRF6 (Botti et al, ), SYNM (de Souza Martins et al, ), and ATP2A3 (Korosec et al, ), were downregulated in late‐stage CIN keratinocytes. On the other hand, stemness‐related genes, such as KLF2 (Gillich et al, ), were increased in the transition of CIN keratinocytes from CIN2 to CIN3.…”